.TH std::match_results::position 3 "2024.06.10" "http://cppreference.com" "C++ Standard Libary"
.SH NAME
std::match_results::position \- std::match_results::position

.SH Synopsis
   difference_type position( size_type n = 0 ) const;  \fI(since C++11)\fP

   Returns the position of the first character of the specified sub-match.

   If n == 0, the position of the first character of the entire matched expression is
   returned.

   If n > 0 && n < size(), the position of the first character of the n^th sub-match is
   returned.

   if n >= size(), a position of the first character of the unmatched match is
   returned.

.SH Parameters

   n - integral number specifying which match to examine

.SH Return value

   The position of the first character of the specified match or sub-match.

.SH Example


// Run this code

 #include <iostream>
 #include <regex>
 #include <string>

 int main()
 {
     std::regex re("a(a)*b");
     std::string target("aaab");
     std::smatch sm;

     std::regex_match(target, sm, re);
     std::cout << sm.position(1) << '\\n';
 }

.SH Output:

 2

.SH See also

   operator[] returns specified sub-match
              \fI(public member function)\fP
